Means and techniques for moving objects particularly useful in water skiing

ABSTRACT

A towing system in which a moving traction means has pickup means thereon movable into engagement with one end of an elongated element, such element being capable of transmitting tension forces but being incapable of transmitting compressive forces and having a body attached to its other end. Such element is maintained taut preparatory to and during the instant of initial connection between the traction means and elongated element so as to extend tautly at a right angle with respect to direction of movement of such traction means whereby the body is accelerated smoothly and without substantial jerk from zero speed to the speed of the traction means.

United States Patent Rixen MEANS AND TECHNIQUES FOR MOVING OBJECTS PARTICULARLY USEFUL IN WATER SKIING Bruno Rixen, Grossbuchwald Post Neumunster, Germany Filed: Apr. 16, 1973 Appl. No.: 351,391

Related US. Application Data Division of Ser. No. 502,229, Oct. 22, 1965, Pat. No. 3,743,278, which is a continuation-in-part of Ser. No. 184,738, April 3, 1962, abandoned.

Inventor:

US. Cl 104/53, 104/172 R, 104/173 Int. Cl A63g l/00 Field of Search 104/53, 172, 173

References Cited UNITED STATES PATENTS 6/1965 Forsman 104/53 Primary ExaminerM. Henson Wood, Jr. Assistant ExaminerD. W. Keen Attorney, Agent, or FirmLyon & Lyon [57] ABSTRACT A towing system in which a moving traction means has pickup means thereon movable into engagement with one end of an elongated element, such element being capable of transmitting tension forces but being incapable of transmitting compressive forces and having a body attached to its other end. Such element is maintained taut preparatory to and during the instant of initial connection between the traction means and elongated element so as to extend tautly at a right angle with respect to direction of movement of such traction means whereby the body is accelerated smoothly and without substantial jerk from zero speed to the speed of the traction means.

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sum '06 or 10 MEANS AND TECHNIQUES FOR MOVING OBJECTS PARTICULARLY USEFUL IN WATER SKIING This is a division of application Ser. No. 502,229, filed Oct. 22, 1965, now US. Pat. No. 3,743,278. which is a continuation-in-part of my copending United States application Ser. No. 184,738. filed Apr. 3, 1962 and allowed by Group 48, Aug. 2, 1965, now abandoned.

The present invention relates to means and techniques for moving objects and to a towing system which is particularly useful in, but not necessarily limited to. a ski system as, for example, for water skiing.

Briefly, the water ski system described herein and embodying features of the present invention involves an endless cable means driven continuously at a constant speed of, for example, 25 miles per hour, above a body of water or a waterway to define generally a closed ski path. In accordance with other important features of the present invention, a novel start system is provided. Using this novel start system, the persons ski equipment, initially at rest, is attached to the constantly moving cable means without necessitating lowering that constant speed of the cable means, for example 25 miles per hour, at which persons, now skiers previously launched in like manner, are skiing. This novel start system results in a skier being accelerated from a stationary or at rest condition to the speed of the cable means with sufficient smoothness to allow persons with little skill to be launched from a standstill condition to a skiing condition.

It is therefore a general object of the present invention to provide improved means and techniques whereby the above-indicated results and purposes may be achieved.

A specific object of the present invention is to provide a start system whereby a skier may be accelerated from an initial standstill condition with sufficient smoothness to a speed for sustaining a ski condition and all without requiring a change in speed of that means used in towing the skier in the ski condition.

Another specific object of the present invention is to provide a start system which does not require a change in speed of that element which tows a skier from an initial standstill condition to a ski condition thereby allowing previously launched skiers to continue their movement without reduction of speed during those intervals when new skiers are being launched.

Another specific object of the present invention is to provide an improved boatless water ski system.

Another specific object of the present invention is to provide a water skiing system useful on small water surfaces and on lakes which are not practical for operation of motorboats.

Another specific object of the present invention is to provide an improved ski system in which, for example, 10 skiers may be towed simultaneously with every participant being able to continue skiing after the first lap of a closed path and with the commencement and changeover of skiers taking place at a high speed and without necessitating a reduction in speed of the cable means used in towing the skiers.

It is of course remembered that the present invention in its broader aspects is not limited to water skiing, but

-is applicable also to, for example, skijoring, slalom ski lifts, and in general. any other arrangements wherein it is desired to tow a body.

Another specific object of the present invention is to provide novel and improved towing means of the kind indicated in which an endless traction member is adapted to run at constant speed on drive and deflection rollers or pulleys mounted on supporting masts that are placed so as to provide a closed path for the traction member.

Another specific object of the present invention is to provide novel and improved towing means of the kind indicated in which means are provided to enable a water skier to be attached to a continuously moving traction member in such a manner that he will be smoothly entrained by the traction member from a standing start without sudden jerks.

Another specific object of the present invention is to provide novel and improved towing means of the kind indicated having means for selective release of a towline, to which a skier holds on, from the traction member.

Another specific object of the present invention is to provide a novel cable means for this purpose featured by the fact that the strands of different cables comprising the cable means arev windings of different hands, i.e., one of the cables has a clockwise extending winding and a companion cable has a counterclockwise ex-' tending winding.

Another specific object of the present invention is to provide an improved towing means involving a pair of cables spaced and maintained with respect to drive and guide pulleys over which they pass such that long life of the system is assured.

Another specific object of the present invention is to provide towing means of this character in which elements of the system may be conveniently assembled and disassembled for repair and replacement purposes.

Another specific object of the present invention is to provide improved means whereby a towline may be attached to and detached from a continuously moving traction member.

Other objects and advantages of the present invention will be apparent from the following description, reference being made to the accompanying drawings wherein:

FIG. 1 illustrates a side view of a water ski system embodying features of the present invention;

FIG. 2 illustrates a plan view of the arrangement shown in FIG. 1 with one of many different possible ski paths being indicated by broken lines;

FIGS. 3 and 4 illustrate constructional features of a towline useful in the systems of FIGS. 1 and 2;

FIGS. 5, 6 and 7 show a side view, a front view, and a plan view respectively, of a special coupling device .for a towline used in FIGS. 1 and 2 constructed for use with the towlines of FIGS. 3 and 4;

FIGS. 8 and 9 show a side view and a plan view, respectively, of a particular embodiment of a towing installation with a band-shaped traction member useful in the systems of FIGS. 1 and 2;

FIGS. 10 and 11 illustrate a side view and a plan view, respectively, of a driving roller arrangement for a traction member constructed in accordance with FIGS. 8 and 9, a support mast being shown only partially;

FIGS. 12 and 13 are views, taken partly in section, of connection elements for cables of the traction member illustrated in FIGS. 8 to 11, such connection elements being illustrated in relation to a direction changing roller and on a scale considerably enlarged with respect to the scale of the preceding figures;

FIG. 14 illustrates a modification of the present invention;

FIGS. l28 illustrate a preferred form of the present invention, FIG. 15 being a top plan view, FIGS. 16 and 17 being views taken generally as indicated by corre sponding lines 16-16 and 1717 in FIG. 15, FIG. 18 being a sectional view taken substantially on line 18-18 of FIG. 20, FIG. 19 illustrating the device of FIG. 18 in side elevation and in a different operating condition, FIG. 19A illustrating more details of apparatus seen in FIG. 19, FIG. 20 being a view taken substantially on line 20-20 of FIG. 17, FIG. 21 being a view taken substantially on line 2121 of FIG. 17, FIG. 22 being a view taken as indicated by lines 2222 in FIG. 15, FIG. 22A being a perspective view of some of the apparatus shown in FIGS. 22, and 26, FIG. 23 being a view taken substantially as indicated by lines 23-23 in FIG. 17 with the tow rope or cable shown in clamped condition just prior to being released, similar to the condition shown in FIG. 18, FIG. 24 being a view like that shown in FIG. 23 with the tow rope clamping mechanism now released from a tow rope and in condition for picking up another tow rope, FIG. 25 being a view in side elevation of the pulling end ofa tow rope or cable in a releasably maintained condition, FIG. 26 being a sectional view taken substantially on line 26--26 of FIG. 25; FIG. 27 is a view in elevation of a modified structure embodying features of the present invention and FIG. 28 is a view taken substantially on line 28-28 of FIG. 27;

FIG. 29 is generally a top plan view of a system schematically portrayed for purposes of describing the start arrangement;

FIG. 30 illustrates a modified start arrangement;

FIGS. 31, 31A, 32, 32A and 33 illustrate other arrangements embodying features of the present invention.

THE START SYSTEM The starting arrangement forms an important part of the present invention and is exemplified in FIG. 29 which illustrates an endless continuously moving traction means 201 comprising an endless overhead driven cable, an elongated tow means 202 attachably and detachably connectable to the traction means 201 and an object or body 203 at a launching area 204. The tow means 202 in a ski system is a rope, cable or chain which is capable of transmitting a tension force only and hence elements of that character are referred to herein generically as a tension and noncompression force transmitting element. One end of the tow means 202 is provided with a means 202A which is attachably and detachably connectable to any one of a plurality of means 201A carried on the traction means 201 for effecting such a connection. The other end of the tow means is provided with a means 2028 which is engaged by the body 203, the body in this instance being a skier in snow, land, or water skiing operations.

The traction means 201, actually in the form of a pair of cables as described later herein, may be driven and guided using conventional means exemplified in FIG.

29 by rollers 206, 207, 208, these rollers being supported on masts 210, 211 and 212 respectively so that the cable or traction means 201 moves above the ground or water and defines generally a tow path. The traction means 201 is assumed to move from the left to the right as indicated by the arrow 214.

A caged pedestal 216 is mounted on the mast 210 for supporting an attendant who controls or supervises the attachment and detachment of the tow means 202 to and from the traction means 201. To effect a connection of the tow means 202 to the traction means 201 such attendant positions the means 202A on the end of the tow means 202 in the path of movement of the pickup or connecting means 201A on traction means 201. The nature of these means 202A and 201A is described later. After the attendant so positions the means 202A for subsequent engagement by the pickup means 201A, the skier 203 pulls the towline or cable 202 taut and maintains the same taut as the pickup means 201A approaches and grasps the tow cable engaging means 202A. At this particular time, it is important that the elongated tow means or cable 202 be extended tautly in a direction perpendicular to the direction of travel of the cable means 201 between the rollers 206 and 207, such direction being indicated also by the arrow 214. At the instant the pickup means 201A engages the tow means 202A and at that particular first instant when it can be said that the tow means 202 is connected to the traction means 201, the velocity of the tow means end 2028 (and also the velocity of the skier 203 pulling the tow means 202 taut) is zero even though at that particular instant the tow means end 202A is traveling at the speed of the traction means 201. Thus as the tow cable end 202A is moved from its position shown in FIG. 29 by the pickup means 201A the skier 203 is accelerated smoothly from a zero velocity. For these purposes it is imperative that initially as disclosed the elongated tow cable 202 have the relationship with respect to the direction of movement of the traction means 201 as described above and as indicated also in FIG. 29; and further, the towline 202 must be held in a taut condition at the time of engagement of the elements 201A and 202A. To realize this latter condition preferably as shown in FIG. 29, the launching area 204, created artificially or by making use of natural surroundings, is angularly disposed so that a skier, in those instances where the towline 202 may become stretched, may use different positions in the launching area to achieve this desired initial taut condition of the towline. Thus, for example, with a short towline a skier may disembark from the launching area 204 at point A; with a longer towline a skier may disembark from point B, and with an average length towline 202 as illustrated, the skier disembarks from point C. Thus the launching area 204 preferably extends angularly, as shown in FIG. 29 with respect to the direction of the traction means 201 with an extension of the axis of the launching area intersecting the direction of travel 214 at an acute angle. It is realized that the 90 relationship illustrated is disturbed somewhat by using points A or B as disembarkation points but the desired results of smooth acceleration without jerks may be accomplished without an exact 90 relationship. In other words, there is some allowable deviation from this 90 relationship although it is preferable that an exact 90 relationship be maintained. As illustrated, the straight stretch of cable or traction means 201, indicated by dimension E in FIG. 29, i.e., that straight stretch between the point at which the pickup means 201A engages and picks up the tow means end 202A and that point at which the traction means 201 passes over the pulley 207 is greater than the length l of the tow means 202. This length 1 is in general dependent upon the linear speed of the cable means 201 so that in general the greater the linear speed of the cable means 201 the greater the length l of the tow means 202. The linear speed of the traction means 201 is sufficiently high to maintain previously launched skiers in a buoyant condition and this may be a speed of for example, 25 30 miles an hour, and it is at this speed at which the traction means 201 is continuously driven without speed reduction. The problem thus solved by this new starting arrangement is that new skiers may be added without diminishing the speed at which other previously launched skiers are traveling. As mentioned previously, the greater the linear speed, the greater in general is the length l of the tow means 202 which means that the start process is of longer duration the greater the speed of cable 201. A favorable relationship between speed and tow means length 1 is, for example, the following: when velocity is l0 meters per second, the length l is 25 meters. Preferably the length 1 expressed in meters is not less than one-third of the speed expressed in kilometers per hour as represented by the following equation:

1 =km/h/3 which expresses the minimum length of the tow means.

Because of these relations and conditions, the skier 203 is accelerated along a curved path indicated at 216. While the skier has some control over the precise shape of the path 216, the actual shape is established predominantly by the physical structure, geometrical relations and conditions. To facilitate the skiers transit he may refer to the series of guide buoys 218, 219, 220 and 221 which establish generally the optimum path with which he should attempt to conform.

It will be observed that the natural course of the path 216 (the skier doing nothing to detour from the natural course) is generally asymptotic to the direction 214 and at all times the cable 202 is under tension during this start process. Further, it will be observed that the skier 203 at all times follows the pull direction of the towline 202 and in movement along the curved path 216 deviations between the instantaneous pull direction of the tensioned towline 202 and instantaneous movement directions of the towed skier as established, for example by manipulation of his skis, are so limited that the resultant movement of the skier is predominantly directed towards the traction element 201; and of importance is the fact that during the starting operation the towline 202 is continuously maintained under tension without possible development of slack in the same. The existence of any slack in the towline 202 during the starting operation is particularly undesirable and may result in the development of excessive jerks in the line at that instant when the slack is subsequently taken up. The term excessive jerk as used above has reference to the fact that the instantaneous pull which may be developed in a slack towline system may be so great as to no longer allow the skier to be pulled by the traction means.

It will be appreciated that the novel teachings and principles explained above in connection with FIG. 29 may be incorporated in apparatus other than ski apparatus. For example, instead of using an endless traction 7 means 201, the traction means may take the form of a self-propelled vehicle using tracks to guide the same or otherwise. Further, the towed body 203 may have its movement confined to a precise curved path and for that purpose the same may be caused to travel on a single or double track system. Such modifications are exemplified further in FIG. 30 wherein a selfpropelled vehicle 224 having four ground-engaging wheels 225 is guided by a rail 227 suspended from bridge structures 228 and 229. A tow element 230 extends perpendicular to the guide 227 and has means 232 as for example in the form of a hook engageable with a cooperating hook means 234 on the vehicle 224. The other end of the tow means 230 is attached to the towed body 236. The towed body 236 in this instance is also a vehicle having four ground-engaging wheels and vertically extending guide means 238 on opposite sides of the curved track 240 for guiding its movement along a curved path corresponding of course to the curved rail 240. This rail 240 is suspended above ground on bridge structures 244, 245 and 229. A continuing guide track 248 is provided which is generally an extension of the track 227 and the same is supported in aligned condition with the track 227 on the bridge structure 250 whereby this track 248 serves also to subsequently cooperate with the vertically extending guide means 224A on vehicle 224 to guide its movement. Also the bridge structure 250 mounts a pair of transient guide members 252, 253 that cooperate with the outboard sides of the vehicle guide means 238 to guide the vehicle 236 such that the guide rail 248 is between the guide means 238 to guide subsequent movement of the vehicle 236. Here again in FIG. 30 there is a smooth movement of the towed body, i.e., the vehicle 236 from a standstill condition to a speed which is the speed of the traction means 224, i.e., the self-propelled vehicle 224. Thus in operation of the system shown in FIG. 30, vehicle 236 is positioned in turn, as shown, with its towline 230 extended perpendicular to the direction of the guide rail 227 and with the hook means 232 on the end of the cable 230 in a path of movement of the cooperating hook means 234 on the vehicle 224 so that as vehicle 224 moves at a constant speed, the vehicle 236 is pulled from a stationary condition along the path 240 to a speed which is ultimately that of the speed of the vehicle 224.

It is, for example, also possible to apply the start system to traction arrangements of the familiar kind, such as railroad systems of all sorts serving to transport people or goods.

The current transportation facilities are by there very nature compelled to stop in order to make people or goods get in or off, thus causing considerable loss of time because of deceleration when applying the brakes and starting, with the stop intervals being the most effective time-consuming factor. In the event of local traffic means which are obliged to frequently stop on their itinerary, the stop intervals often equal the total running time. When employing the described start principle, the total running time of such facilities might be reduced by 50 percent, i.e., average speed would be doubled. On the other hand, there are considerable losses of energy resulting from braking and starting again, which would not occur any more.

FIG. 32, for instance, describes how a traction vehicle with self contained propulsion 501 with wheels 502 runs on two rails 503 as track. A tow element 504 extends perpendicularly to the track and is at its one end provided with means, for instance hook means 505, engaging, for example, with other hook means 506 secured to the traction means. The towed vehicle 507 is fastened to the other end of the tow element. Said vehicle also has wheels 508 which are not track-bound in this case. Under the tractional influence of the traction vehicle, the towed vehicle 507 whose longitudinal axis at the instant of the transmission of power predominantly runs perpendicularly to the track of the traction vehicle 501, moves on a curved line 509 towards the path of movement of the traction vehicle and follows it. The towed vehicle 507 may then be pulled towards the traction vehicle 501 by the length of the tow element 504 and coupled to it in order to allow people or goods accomodated therein to get into the traction vehicle, or to permit those people and goods that must be transported to the next station to leave the traction vehicle for the towed vehicle. Shortly before arriving at the next station, the towed vehicle is disengaged from the traction vehicle and is then attached to a vehicle already waiting there in the manner described above. Thus there is ensured a continuous interchanging of towed vehicles without intermittent stopping being necessary.

In a modified system described by FIG. 31 the towed vehicle 510 is equally track-bound. On a curved rail 511 it is in the start range brought up to the path of movement of the traction vehicle 501. This curved rail changes by means of a switch 512 over into the rail track 513 of the traction vehicle once the process of acceleration has substantially come to an end. The run of the curved rail predominantly corresponds with the line which under the tractional influence of the traction vehicle the towed vehicle, even without being trackbound, would follow via the tow element, in the event that its instantaneous direction of movement substantially corresponds to the instantaneous direction of the elongated tow element. As this curve in the first initial range of the acceleration has a strongly bent run with quickliy changing direction and because, on the other hand, the towed vehicle may have a considerable straight length, it is advisable in this case to deviate from the exact run of the curve in this range by flattening the initial curvature of the track more strongly so that at the beginning it does not follow a course in the direction of the elongated tow element when starting, i.e., perpendicular to the track of the traction vehicle, but at this moment already runs at an angle to the tow element which may amount to 45. Moreover, it is use ful to prolong the rail track, at the same angle, from the point of connection of the towed vehicle with the tow element at the instant of starting in order to be capable of taking up the already waiting towed vehicle.

The curved rail track may join the rail track of the traction vehicle by means of a switch 512, but may also after the towed vehicle has reached the speed of the traction vehicle (see FIG. 31A) continue running in parallel with the track of the traction vehicle in order to avoid switches. In this system (FIG. 31A), the towed vehicle may also bepulled towards the traction vehicle parallel with it in order to ensure the changing of people or goods.

An example of how the traction vehicle in FIGS. 31 and 32 and the towed vehicle in FIG. 31 is executed will be furnished by FIG. 33. The towed vehicle in FIG. 32 is shown in FIG. 32A. The rails employed for the traction vehicle ensure that the towed vehicle can travel behind the traction vehicle without being impeded in the least by the rails of said traction vehicle.

PREFERRED FORM OF FIGURES 15-28 Features of the start system previously described are incorporated in the preferred form of the invention shown in FIGS. 15-28 wherein the traction means 301 in the form of a pair of endless cables 302 and 303 continuously move at a constant speed around the pulley pairs 305, 306, 307, and 308 in that order, the pulley pair 305 being drive pulleys and the other pulley pairs being guide pulleys.

Each of the guide pulley pairs 306, 307, 308 are supported so-called flying pulleys as typified by the arrangement shown in FIG. 16 wherein the pulley pair 308 includes an upper pulley 308A and a lower pulley 3088 around which the cables 302 and 303 are trained respectively. The pulleys 308A and 3083 may be fixed to a common shaft 308C which has its upper end rotatably supported in a bearing housing forming part of the support 308D. Also as shown in FIG. 16 a mast 310 extends vertically upwardly at an angle of approximately 45 from the bank 311 that defines the waterway 312 and a guy wire 314, having one of its ends anchored in the ground and the other one of its ends attached to a shackle 316 pivotally mounted on the plate 318 at the upper end of mast 310, serves to maintain the upper end of mast 310. A cable 320 extends from a shackle 322 pivotally mounted on plate 318 and around a first sheave 324 and a second sheave 325 to a conventional adjustable tensioning mechanism 326, the shackle 322 and sheave 325 being pivotally mounted on the plate 318. The outer housing member of the sheave 324 is in the form of a shackle through which a cable 328 extends, one end of the cable 328 being affixed at a lower portion of support 308D and the other end of cable 328 being affixed to the upper end of the support 308D. It will be seen that this arrangement provides a rather flexible support for the pulley pair 308 with the same being capable of moving vertically and horizontally and thus the same is referred to as a flying" roller assembly. It will also be seen that this arrangement allows adjustment of the rotational axis of the roller pair 308, the same preferably being vertical and this adjustment may be accomplished by shortening or lengthening the cable 320, using for that purpose the adjusting device 326.

Since the other two guide roller pairs 306 and 307 are supported in like manner as the pulley pair 308 the masts and guy wires associated with the same have the same reference numerals as in FIG. 16.

The drive pulley pair 305 is supported in a different manner than the guide pulley pairs as shown in FIG. 22 wherein the drive pulley pair 305 comprises an upper drive pulley 330 and 'a lower drive pulley 331, these pulleys 330 and 331 being mounted on the oppositely extending stub shafts of a conventional differential 334 of the type found for transmitting rotational energy to the rear wheels of an automobile. The stationary housing 335 of the differential is secured by arms or braces 337 to the outer end of a frame member 338, the other end of the frame member 338 being secured to the mast 339 which is suitably anchored on the bank 311 using also conventional supporting guy wires 341 and 342. The input shaft 343 of the differential 334 is driven by a belt or chain 345 passing over suitable pulleys on the shaft 343 and an elongated shaft 346 having one of its ends driven at a constant speed by a suitable prime mover illustrated in FIG. 22 as a diesel engine 348, the engine 348 being secured to the horizontally extending frame member 338. The guy wire or cable 350 extends between outer points of the mast 339 and support frame 338 to help support the load.

Using this arrangement it will be seen that the traction means 301 in FIG. is driven in a counterclockwise direction by the drive pulley pair 305 as indicated by the arrows 352 with the launching area 354 (corresponding to the launching area 204 in FIG. 29) being disposed so that a towline 355 (corresponding to the towline 202 in FIG. 29) is attachable to the traction means 301 as the same travels around the drive pulley 305 or shortly thereafter as explained in more detail below. Here again the towline 335 just prior to the time of attachment to the traction means 301 is maintained by the skier in a taut condition, for that purpose the length of the towline 355 being equal to the distance from the launching area 355 to the point of attachment with the traction means; and of importance, as described previously, the towline 355 extends at that time generally perpendicular to that section of the traction means between the pulley pairs 305 and 306. These towlines 355 are usually of rope and hence the same after use may stretch. To accommodate slightly different lengths of towlines 355 the launching area 354 may be angularly disposed as shown in FIG. 15 so that a prolongation of its axis intersects a prolongation of that section of cable between pulley pairs 305 and 306 at an acute angle, all as described above in connection with the launching area 204.

Also as indicated in FIG. 15 other skiers may be using the system, i.e., may already be launched and skiing prior to and during the launching of a skier from the launching area 354. The launching area 354 may be, for example, in the form of a pier which provides a flat surface that may be, for example, I or' 2 feet above the water surface so that a skier may be launched while sitting on the pier or launching area while pulling the towline 355 to maintain it taut. A more experienced skier may be launched successfully from a standing position on the pier, timing his movements so that he jumps from the pier at the time the end of the towline 355 is being engaged by the traction means 301 and so as to assure at all times the existence of a tension force in the cable 355 both prior to engagement of the cable 355 with the traction means 301 and during his transition from the pier onto the water.

The traction means 301, as mentioned previously, in-

The upper section 361B (like the upper section tion 361A is disposed and through which the previously mentioned pivot pin 363 extends. Also this upper section 3613 is formed with an extended portion 366 with a specially shaped grooved outer portion 366A within which the upper cable 302 is secured by a generally U- shaped clamping member 367. Also, this specially constructed upper portion 3613 is formed with a circular opening 369 in which a cable clamping structure is secured.

As seen in FIG. 20, the generally U-shaped clamping element 367 is provided with a pair of inwardly extending finger portions 367A which are sandwiched between a square or rectangular head 370A and bolt 370 and a shouldered washer 372 within the hollow portion 369, such inwardly extending portion 367A being so held in clamped condition by a nut 374 threaded on bolt 370. A shouldered washer or plate 375 has a portion extending into the hollow portion 369 and a flange portion engaging the element 361B and Belleville type springs 379 are disposed between the flanged element 375 and a washer 376 backed by a nut 378 on bolt 370, the springs 379 being partially housed within a cylindrical casing 380.

As seen in FIG. 17, diagonally opposite end portions of spacer elements 361A, 360A are joined by a pair of flexible cords or cable elements 382, 383, each of which is adjustably tensioned. These elements 382, 383 are capable of course, of transmitting only tension forces and are adjustably tensioned using conventional adjustable means 384, 385 each of which involves generally a threaded stud 387 with the socket 389 being held in adjusted position by a lock nut 390. The lower ends of the cables 382, 383 are secured in socket portions 392 using securing nuts 394. The previously mentioned studs 387 are secured to suitable brackets 393 on spacer elements 360A and 361A. It will thus be seen that the structure thus far decribed involves like clamping structures at each of the four corners of a rectangle with also the vertical legs of the rectangle each com prising a flexible element pivoted at 363. This structure so mounted on the continuously moving cables moves to the right as indicated by the arrow395 in FIG. 17 and it will be seen that the trailing spacer element 361 is exactly like the leading spacer element 360 with the exception that the trailing spacer element 361 is provided at its lower end with a towline pickup means 400 for attachment to and detachment from an end of a towline 399 as indicated in FIGS. 18 and 19 and now described in connection with FIGS. 17, l8, l9 and 20.

The lower portion of the spacer element 361A comprises generally a tubular portion 401 which is secured by a pin 403 in a socket formed in the cable clamping element 405 like the cable clamping element 3613 with the exception that now the cable clamping element 405 is rigidly connected to the tubular element 401 and is provided with a lower extending portion 407 formed to provide one element of the releasable clamping device 400. The other element 409 of the releasable clamping device 400 is pivotally mounted and spring urged using the construction now described. The clamping jaw 409 is pivotally mounted on a pin 410 having one of its ends secured in a socket portion of the cable clamping element 405 by a pin 411 (FIG. 23). The clamp jaws 409, 407 are normally urged together by a coil tension spring 413 having one of its ends connected to the element 409 and the other one of its ends secured to a pin 415 on the tubular spacer element 401. Also, as seen in FIG. 17 and 20, a cam roller 416 is rotatably supported on the clamp arm 409 at a point remote from its pivot point 410 so that the towline clamp 400 may be automatically opened by engagement of the cam roller 416 with a cam track 417 (FIGS. 19 and 23) this cam track 417 being mounted on the supporting structure arm 338 (FIG. 22) so as to achieve an automatic opening of the clamp 400 when desired as indicated in FIG. 19.

This cam track 417 is some cases may be stationarily mounted in which case for each revolution of the traction means, i.e., one trip for a skier, he is automatically detached from the traction means but preferably this cam plate 417 is movably mounted on the arm 338 as, for example, by pivoting the same so that the same may be selectively moved either in the path of movement of the cam wheel 416 to open the clamp 400 or such cam track 417 may be positioned out of the path of movement of the cam wheel 416 in which latter case of course, the skier is allowed to continue for more than one trip. Preferably the cam track 417 is in normal position to cause opening of the clamp 400 and is movable by an operator to a position wherein there is no opening of the clamp 400.

For the aforementioned purposes, the end 399 of the towline 355 (FIG. 25) may be formed from a metal rod 420 bent at its lower end to provide an eyelet 421 for attachment with a towline rope 355. This rod 420 is formed with two cylindrical portions 421,422 on opposite sides of a spherical portion 424. The bulbous end portion which is in the form of a frustocylindrical portion 427 and which is actually that part which is engaged by the clamping means 400, is secured to the cylindrical portion by a flexible portion 430, such flexible portion 430 being in the form of a tightly wound spring that holds the end portion 427 in an extended position but which'allows some flexing of the same with respect to the spherical portion 424 which prior to engagement with the clamp means 400 is releasably maintained in a socket provided by a pair of spaced leaf springs 431, 432 as shown in FIG. 25. These leaf springs 431, 432 are provided with apertured portions 431A, 432A which engage the spherical portion 424. Also as shown in FIG. 25, the rod 420 may be provided with a flanged portion 425 that may serve as a guide for an operator positioning the tow cable end 420 in the releasable holder shown in FIG. 26. Instead of there being two leaf springs 431, 432, only one spring may be provided with the other element then being rigid.

The cam track 417 of FIG. 23 is so positioned that it causes the clamp 400 to be released at the time that the cable section, between pulley pairs 305 and 308 and carrying the clamp 400 of FIG. 19, isstill traveling along substantially a straight line so as to gain advantage of the inertia of the towline end 399 in freeing itself completely from the clamp 400. In other words, the clamp 400 is open substantially at the time shown in FIG. 23 when and as the cable section immediately above the clamp is still substantially tangential to the roller 331 and before that cable section begins its journey around the roller 331. After releasing a towline cable end 399 the clamp 400 returns to a condition wherein it is effective (after a substantially rotation of the roller 331 from the position shown in FIG. 23 to the position shown in FIG. 24) to pick up another cable end 399 and thus to launch a new skier. Thus during the first part of this 90 movement of roller 331 a previously launched skier is released, and at the end of such 90 travel, a new skier is launched. To assure cooperation between the towline end 399 and the clamp 400, the jaws of the clamp are preferably provided with forwardly extending arm portions 409A and 407A which define generally a guideway to assure travel of the end 427 between the jaws 409 and 407 as shown in FIG. 18.

FIGS. 27 and 28 illustrate a cable clamping structure which may be substituted for any one of the four or for all of the four cable clamping structures shown in FIG. 17; the purpose of the arrangement shown in FIGS. 27 and 28 is to provide a clamp for cable ends to facilitate assembly and for repair and replacement purposes when different sections of the cable are to be removed and replaced. In this instance, one of the cables, illustrated as cable 302 in FIGS. 27 and 28, actually comprises two sections of cables 302A and 3028 having their ends lying in conforming grooved portions 366B, 366C of a cable clamping member such as the cable clamp 366 in FIG. 21 but in this instance the ends of cables 302A and 3028 pass through a central apertured portion 366E which is also grooved to provide a seat for the cable ends and also to accommodate a wedge member 366F which is drivable between the adjacent cable ends to thereby wedge the same in a locked position. For this purpose the wedge 366F is also preferably provided with grooved portions in which the round cables 3028 and 302A are seated. Once the wedge 366F is positioned as shown in FIG. 27, it may be secured by, for example, a wire to the cable clamp member 366 in FIG. 27.

It will be seen that the system thus allows convenient replacement and adjustment of cable sections. Should either an upper or a lower cable section break the traction system then automatically comes to rest (safety feature) because of the mechanical differential 335 which then, due to the breaking of the cable section, is rendered ineffective to translate movement of the continuously rotating shaft to the unbroken cable.

The spring 413 (FIGS. 17-19) is of such strength that it allows the tow cable end 427 to release itself when more than a predetermined tension is developed in the two cable, as, for example, to prevent a skier from being dragged through the water in a dangerous condition. The particular shape of the tow rope end then functions as a cam in camming the jaws 407, 409 open against the action of spring 413.

In operation of the system an attendant is in a cage 430 (like cage 216 in FIG. 29) wherein he is in a position to place the tow rope element 399 in a releasable clamp having the resilient jaws 431, 432 extending from a stationary support 432 as seen in FIGS. 26 and 22. In such position the tow rope end 427 then extends in the path of movement of the pickup means 400 (FIG. 17) on the continuously moving traction means. While the tow rope end is thus positioned a skier pulls and maintains the same taut. When and as the pickup means picks up the tow rope end the start process described above is initiated. Subsequently after the skier completes one or more laps the skiers tow rope is re leased by the attendant positioning the member 417 (FIG. 19) in the path of the roller 416 to thereby cause the pickup means to be released. This release occurs as the pickup means travels around the drive pulley and such pickup means thereafter becomes effective after traveling around only approximately 90 of the drive pulley to pick up a new skier. This process continues with the attendants job being to insert towlines in the clamp of FIG. 26 (to add skiers) and to position the ac- 4 tuating member 417 (to subtract skiers).

The attendant, for these purposes, may remain seated on a chair 440 mounted on a platform forming part of a cage 441 where it is convenient for him to insert the ends of tow ropes 335 in a releasable clamp as shown in FIG. 22A (for purposes of adding a skier) and to grasp and move the handle portion 417A (FIG. 19A) of the cam actuating member 417. As illustrated, the member 417 is pivoted at 422 on the lower end of a vertically extending stationary support element 444 to normally assume the adjusted full line position shown wherein the end of an adjusting bolt 446 threaded in an extension 4178 engages the support element 444. In that position illustrated in full lines the cam track element 417 is in the path of movement of the cam wheel 416 (to release a skier as shown in FIG. 19). When it is desired to allow a skier to continue for another lap around the watercourse the attendant grasps the handle portion 417A and lowers it to thereby move the cam track 417 to the dotted line position in FIG. 19A wherein the stop member 450 is engaged and element 417 is out of the path of movement of the cam roller 416. It will be understood that instead of the element 417 being normally in the path of movement of cam roller 416, the element may be so pivoted that an external force is required to be applied by the attendant to release a skier from the system.

Afterrelease of a towline it, of course, then drops into the water under the cage 441 where it is fished out by other personnel who have facilities to raise the towline to the attendant in cage 441. Such facilities may, for example, be an endless rope 460 (FIG. 22) with suitable towline engaging hooks (not shown) thereon passing over a pair of sheaves 461, 462, the sheave 462 being provided with a crank 463 rotatable by a person on shore to raise the end of a towline to the attendant in cage 441 who then releases the towline from the rope 460 and releasably attaches it to, temporarily, a support structure (not shown) from where the tow rope ends are taken individually by the attendant as needed and placed in the releasable clamp shown in FIG. 22A for subsequent automatic pickup by the pickup device 401) (FIG. 17) on the continuously moving cable pair 302, 303. During the time the tow rope cable end is thus being maintained as seen in FIG. 22A. the person (potential skier) maintains the line 420 taut and for that purpose the towline is provided with the flanged portion 425 which is then being pressed against the spaced clamp elements 431, 432. The towline thus maintained taut in a 90 relation to the path of travel of pickup device 400 continues to be tensioned when and as the pickup device 400 engages the tow rope end 427 and initiates the movement of the person holding the other end from zero velocity condition to the velocity of the pickup device with a smooth acceleration unaccompanied by any jerk which would otherwise cause the person to fall into the water.

ARRANGEMENT OF FIGS. 1-14 Referring to FIGS. 1 and 2, at or near the shore 1, there are located masts 2, 3 and 4 either partly submerged or on the dry land. and inclined toward each other. The masts 2 and 3 are inclined at 45. The mast 5 is shown disposed on the sea bottom. The mast 2 carries at its head a drive assembly 6. Stays for the masts may be arranged adjustable in length for adjusting the axial inclination of the driving or guide or deflector rollers when the drive assembly or the deflector rollers are rigidly or directly arranged on the mastheads. The circulating line or cable drive means 7 runs over the deflector or guide roller 8 of the mast 3, over the deflector roller 9 of the mast 4, over the deflector roller 10 of the mast 5 and over the drive roller 11 of the mast 2. The deflector roller 9 is connected to the mast 4 by support lines 12 and 13 and the deflector roller 10 to the mast 5 by support lines 14 and 15. The deflector roller 11 is directly connected to the mast 2 without support lines. The mast 2 is held in position by stays 18 and 19 and the mast 3 by stays 20 and 21. Stays 22 and 23 hold the mast 4 to incline the deflector roller 9 so that it can remain in position without a third stay on the water side. The mast 5 is held in its inclined position by a pendulum support 24, a connecting line 25 being fixedly connected to the head of the mast 5 and the pendulum support 24 and to a weight 65 disposed on the sea bottom. In order to keep the pendulum support 24 and the mast 5 in equilibrium without the tension of the circulating line 7, the pendulum support may be provided with a support, or the head of mast 5 may be connected to a weight disposed on the sea bottom, which weight is greater than the opposed weight of the pendulum support. The stays can be fixed to threaded, corkscrew-like screw members 66 which, particularly for anchoring to the sea bottom, provide great security and simple installation.

A starting pad 26 (FIG. 2) is disposed opposite the drive roller 11 at a distance from the line 7 corresponding to the length of the towline 27 so that the towline 27 in the start position extends at right angles to the circulating line 7. In this way, the initial part of the tow path 28 is on the starting pad 26 so that the water skiers transition into the water takes place at the speed required for selfisupport. The particular inclination of the starting pad 26 to the surface of the water can be selected so that the mass acceleration force plus the friction resistance on the pad 26 is equal to the mass acceleration force plus the friction resistance on the water.

For connecting the towline 27 with the continuously moving circulating line 7 means are provided which are described in detail below. The towline 27 itself is shown in FIGS. 3 and 4. It has, at one end, two separate loop members 37 and 38. The loop member 38 extends through a hole 40 at one end of a handle bar 36, while the other loop 37 is disposed in a circumferential groove 41 at the opposite end of the handle bar 36 so that said loop member 37 is readily releasable from the handle bar 36. Thus, when the skier drops the handle bar and it strikes the water, it releases itself from the loop member 37 and is towed in a straight line beneath the circulating line. whereby a comparatively smooth movement is brought about which allows the handle bar to run uniformly along the surface of the water without oscillation, so that the circulating line is not subjected to oscillation by handle bars towed thereby. The handle bar is suitably of a very light material and advantageously with a flexible end portion, in particular at the end provided with the hole 40. In a modified embodiment the handle bar may be provided at both ends with circumferential grooves corresponding to the groove 41 to render it completely releasable The releasable arrangement of at least one towline end on the handle bar is an important feature.

The towline 27 is provided at the end thereof opposite to said loop members 37, 38 with a coupling member 34, 35 the structure and function of which will be described below in connection with coupling means 42 carried by the circulating line and permitting not only satisfactory coupling of the towline to the circulating line but also uncoupling of the towline after a skier leaves the circulating line after completing the desired number of runs or after falling down. Such an arrangement for uncoupling a towline is an important safety measure. An important feature of the coupling device 42 is a clamp arranged to close under the force of a spring and comprising arcuately extending jaws which diverge in the closed condition for a purpose to be explained.

The coupling device 42 is described below in connection with a circulating line of the general type shown in FIGS. 7.

In FIGS. 5-7 the coupling device 42 is shown secured to the spacing bar 113, and the lower drive roller 117 is indicated in broken lines with reference numeral 43. The coupling device 42 comprises a lower finger 44 and an upper finger 46. The lower finger 44 is fixedly connected to a line shackle 47. This line shackle is, for example, a member of Ushape with arms 48, 49 of different lengths. In the shorter arm 48, the circulating line 111 is fixed while the spacing bar 113 is connected with the upper arm 49 which has the upper finger 46 pivotally connected therewith by means of a pivot pin 53. With the drive rollers mounted in a horizontal position (as is the drive roller 43 in FIGS. 5 and 6) the fingers 44, 46, when seen in a plan view, are shaped substantially as shown in FIG. 7, i.e., they are rather sharply curved at 50. As seen in elevation as shown in FIG. 5, the fingers 44, 46 have diverging free end portions, and it will be seen in FIGS. 5, 6 and 7 that the finger 46 beyond the pivot pin 53 has an extension 54 which projects in the general direction towards the center of roller 43. Said extension is connected with the spacing bar 113 by means of a spring 56 to bias the finger 46 toward the finger 44, as shown in FIG. 6. The cable 111 is secured in a conical pocket 58 in the line shackle 46 by means of a wedge 59, as shown particularly in FIG. 7, and the line shackle has curved surfaces 60, 61 for engagement with the cable 111 at both ends of the line shackle 47.

A lever 62 is pivotally connected at 70 with the housing of the differential 133 and has a pivotal connection at 71 with one end of a link 72 which has its other end pivotally connected at 73 with a lever 64 which, in turn, is pivotally mounted at 63 on the housing of the differential 133. The free end portion of lever 62 is slightly curved as shown in FIG. 5. By moving the righthand end (FIG. 5) of the lever 64 upwardly an operator may bring the lever 62 into the path of movement of the extension 54 of finger 46 to thereby cause said finger 46 to move away from the finger 44.

The coupling member 34, 35 comprises a steel rod 35 having one end attached to the towline 27 and being provided at the other end with a generally ball-shaped member 34 which preferably is wedge-shaped on one side as shown in FIG. 4, said wedge-shape conforming to similarly inclined surfaces on the fingers 44, 46 in the region of the curved portions thereof at 50. A sleeve 57 of rigid material is secured to the rod 35, as indicated in FIG. 4.

In operation, with the roller 43 rotating continuously in the direction indicated by the arrow in FIG. 7, a water skier who intends to use the towing means takes up a position on the launching pad 26 (FIG. 2) close to the end thereof facing inward. His skis are on and he holds on to the handle bar 36 of a towline. By means of a suitable tool (not shown) an attendant in the basket l6 hooks on to the sleeve 57 on the steel rod 35 and holds said rod in front of the diverging portions of the fingers 44, 46 of an approaching coupling device 42 so that said rod 35 passes into the space between the fingers 44, 46 and the ball 34 is caught in the curved portions 50 of said fingers. The rod 35 is then automatically released from the aforementioned tool, which is called a draw-out device, and the skier is pulled off the pad 26 onto the water surface.

Since at the starting moment the towline 27 is substantially perpendicular to the direction of movement of the adjacent portion of the circulating line 7 the skiers movement is initiated practically without any sudden jerk and if he simply follows the pull by the towline 27 he will with smoothly increasing speed approach the circulating line 7 along a path similar to the first portion of the broken line 28 in FIG. 2. In order to avoid slackening of the towline 27 and a sudden jerk in the same when the circulating line 7 passes around deflection rollers, such as 8, 9, or 10 the skier should approach such rollers at a certain angle which varies with the speed of the circulating line 7 and the angle of change of direction at such rollers. The optimum path for each such combination of conditions may be marked by means of small anchored buoys, as indicated at 64' in FIG. 2.

With the lever 62 in the position shown in FIG. 5 it is evident that the extension 54 of the finger 46 will engage said lever 62 and be thereby caused to turn to the position indicated by broken lines in FIG. 6, thus separating the finger 46 from finger 44 sufficiently to release the ball member 34 and thereby the towline 27 from the circulating line 111. The attendant in basket 16 may, of course, prevent such release, if undesired, by properly manipulating the lever 64 to move the lever 62 out of the path of the extension 54.

In particular, the construction of the ball 34 with ,a cone as the wedge provides an advantageous overload coupling, since according to the adjustment of the spring 56 the clamp opens on overloading. Thus, when a fallen skier does not release the handle bar of the towline, the pull on the towline increases so strongly that the ball, or in particular the cone, on separating of the fingers 44, 46 slides out therefrom.

Reference is now made to FIGS. 8 to 13. In these figures, a construction is illustrated which operates with a circulating member or traction line which extends in a plane, the parallel connection of two lines being shown in the example. It is pointed out that corresponding connection of several lines can be provided. The connection of two or more parallel lines at a predetermined spacing is particularly advantageous in larger installations and, in particular, in view of the lifeyand safety of operation, as well as the simplification of the coupling operation, which is easier to carry out with such a multiple line than with a single line. Furthermore, a considerable advantage resides in the use of a double line in that the influence of twisting of the line is avoided.

In FIGS. 8 to 13, the circulating line is a pair of line runs 110 and 111 which are held accurately spaced by the spacing bars 112 and 113 and the diagonal stays 114 and 115, in which the driving rollers 116 and 117 and the other deflector rollers and lower support rollers 118 and 119 are also mounted. The rollers are mounted on masts of which the upper end of one is indicated at 136. This mast can furthermore be constructed and supported like the masts 2, 3, whereby the swinging of the mast the angle of the rollers 116, 117 with respect to the horizontal is adjustable; or a roller arrangement can be supported so as to be adjustable in angle according to the system described with reference to FIGS. 1 and 2.

The stays 114 and 115 are provided for accurate adjustment using corresponding tension bolts 120. The rear connection bar 113 has a forwardly inclined outwardly pointing coupling clamp 121. Around this is disposed the middle part of a towline 27 which in this form comprises a single cable or rope having both ends suitably attached to a handle bar. The coupling clamp 121 corresponds to the coupling 42 in FIGS. 5-7.

The connection of the spacing bars 112, 113 to the circulating lines 110 and 111, in this case, may be a clamping connection, as shown in FIGS. 11 and 12, since it is possible by use of a right-hand and a left-hand twist line or by spacing the lines 110 and 111 sufficiently far apart to prevent any twisting moment in the lines from raising the line to or above the level of line 110. In FIG. 13 the spacing bars 112, 113, are shown to have a bend before the circulating line 110, 111. A tube member 122 is welded to this bend. In the tube member, a threaded member 123 is provided which at the bottom, beneath the tube member 122, has a portion 124 which fits snugly in the V-groove of the roller 116 except that its sides form a somewhat smaller angle than that of the V-groove. Through this portion 124 there extends a hole 125 having the same diameter as the circulating line 110, the lower wall of which boring is formed with a circular arc corresponding to the line roller 116. On the tube member 122, twowing-like members 126 are welded which extend substantially parallel with the hole 125 and have a groove in their bottom edge for accommodating the line 110, as indicated in FIG. 12. For some distance to both sides of the center line of the threaded member 123 the curvature of the portions of said members 126 contacting the line 110 is concentric with the periphery of the roller 116, said curvature being joined toward the ends of said members 126 by portions curved in the opposite direction and having a radius substantially equal to that of the bottom of the V-groove in roller 116. These arcuate surfaces of the flanges 126 ensure that the circulating line extends at these curves with a comparatively large radius of curvature when it moves to or from a deflector roller, i.e., when the towline runs around a roller. Corresponding conditions hold truealso for the mem bers 60, 61, in FIGS. 5-7, the line-guiding surfaces of which extend arcuately, in a similar manner. A

threaded pin 128 additionally ensures that the portion 124 remains in correct position. The spacing bar 112 is welded at a point radially beyond the line roller 116 to the tubular member 122 at right angles to the members 126 (FIG. 12) and is curved toward the plane of the circulating lines 111 and 110. The stay 114 is connected by means of the angle lever 129 to the tubular member 122 which is welded to the tubular member rearwardly inclined in the direction of the stay. The free arm of the angle lever 129 is so long that the rounded boring 130 for receiving the stay 114 lies below the bottom of the V-groove in the roller 116 by about half the thickness of the circulating line 110, (FIG. 12). This arrangement of the angle lever 129 also has the purpose of locating the stays 114, 115 on the inside of the curve formed by the rotary line in passing a roller.

The driving rollers 116 and 117 (43 in FIGS. 5-7) are themselves driven by an electric motor 131 via a drive 132 with or without coupling and a differential drive 133, which drives are mounted in a framework 134 and are connected by the connection member 135 to the mast 136 fixedly or also adjustable in inclination.

The differential 133 has the advantage that on breaking of one line the roller for the other line stops, whereby a higher safety factor is provided. Two rollers 137, 138 are mounted on the mast 136 on horizontal axles. ()perating lines 143 are trained over said rollers 137, 138 and have secured thereto a coupling frame 139 which is slidable along the mast 136. Two clamps 140, 141 are secured to said frame 139 in such a position that the towing line 27 can be readily attached thereto, as shown. The attaching of the towing line 27 is preferably accomplished by lowering the frame 139 by manipulating the operating lines 143 until the clamps 140, 141 can be reached by the operator whereupon the frame 139 with the towing line 27 attached is moved upwardly along the mast 136 to a readinesss position slightly below the position shown in the drawing. When it is desired to attach the towline 27 to an approaching clamp, or hook, 121 the frame 139 is moved further upwardly into engagement with an abutment member 142 which retains the frame 139 in proper position for the hook 121 to strike against the towline between the retaining clamps and 141 and raises it from these, whereby the towline is carried on by the circulating line. The acceleration is, for uniform constant circulating line speed, smaller as the towline is longer and furthermore the starting point can thus be perpendicularly spaced from the circulating line.

In FIG. 14, a special system is shown for guiding the line according to the invention, in which the traction member comprises two lines 110, 111 according to the illustrations in FIGS. 8 to 11. For explanation of this embodiment, a guide section is shown with three masts 150, 151, 152. Each mast carries two rollers 153, 154; 155, 156 and 157, which are advantageously rotatably supported independently of each other by means of a support arrangement 159 or 160 arranged in the middle, whereby the unit 159 or 160 can for example also be a driving group corresponding to the parts 131, 132, 133 shown in FIG. 10.

Tensioning of the masts in order to adjust these into predetermined positions of inclination, or links in the roller supports for giving the roller axes predetermined inclinations, are not shown in FIG. 14. According to the perspective view, the traction member can for ex- 

1. In a system wherein it is desired to accelerate a body from a substantially stationary condition to a speed commensurate with the speed of a moving traction means, means defining a path of movement of said traction means, an elongated element having one of its ends attachable to said means with said body being attachable to the other end of said element, said element at the time of its attachment to said traction means extending substantially perpendicular to said path, said traction means being a self-propelled traction vehicle running on its said path of movement on a track and wherein said body is a towed vehicle moving under tractional influence exercised by said traction vehicle on said elongated element on a curved line towards said path of movement of said traction vehicle, said curved line taking such a course that the instantaneous direction of movement of said towed vehicle predominantly corresponds to the instantaneous direction of said elongated element and wherein said curved line of said towed vehicle and said track of said traction vehicle ultimately extends in the same direction once said towed vehicle has substantially reached the speed of said traction vehicle.
 2. In an system as set forth in claim 1, in which said body is a track-bound towed vehicle, too, and wherein said curved line has been constructed so as to form a curved track for said towed vehicle.
 3. In a system as set forth in claims 2, in which said track of the traction vehicle is straight for a distance which is at leAst equal to the length of said element.
 4. In a system as set forth in claim 2 wherein said towed vehicle is pulled toward said traction means by the length of said elongated element once said towed vehicle has substantially reached the speed of said traction vehicle so that said towed vehicle may be directly coupled to said traction means.
 5. In a system as set forth in claim 2 in which said tracks of said traction vehicle and of said towed vehicle are rail means arranged in a plane and in which there are guide means at the lower part of said vehicles engaging with said tracks.
 6. In a system as set forth in claim 2 wherein said towed vehicle at the initial instant of the transmission of power thereto from said traction means is away from the point of connection between said elongated element and said traction means and wherein the longitudinal axis of said towed vehicle then runs in the traveling direction at said instant in the direction of said elongated element at an angle of at least zero but at most 45* therewith, said curved track being prolonged by at least the length of said towed vehicle beyond its point of connection with said elongated element and running in the range of this prolongation in substantially the same direction as said axis.
 7. In a system as set forth in claims 1, wherein said towed vehicle is pulled towards said traction vehicle by the length of said elongated element once said towed vehicle has substantially reached the speed of said traction vehicle so that said towed vehicle may be directly coupled to said traction vehicle.
 8. A system as set forth in claim 1 in which said curved line of said towed vehicle and said track of said traction vehicle are the same once said towed vehicle has substantially reached the speed of said traction vehicle.
 9. A system as set forth in claim 1 in which said curved line of said towed vehicle and said track of said traction vehicle extend generally parallel to each other once said towed vehicle has substantially reached the speed of said traction vehicle. 